1. Field of the Invention
The present invention relates to a control system and a switch device thereof, and in particular relates to a control system and a switch device for a motor.
2. Description of the Related Art
Referring to FIG. 1, a conventional control system 2 is electrically connected to a motor 1 and controls the operation of the motor 1 according to an external power VIN. The control system 2 comprises a driver 10, a switch element S, a filter capacitor CS, a first diode D1, and a second diode D2. The switch element S is electrically connected to the external power VIN. The first diode D1 is electrically connected between the switch element S and the motor 1. The second diode D2 is electrically connected to the switch element S. The driver 10 is electrically connected between the second diode D2 and the motor 1. One terminal of the filter capacitor CS is electrically connected between the first diode D1 and the motor 1, and the other terminal thereof is electrically connected to a ground. When the switch element S is turned on, the external power VIN is transmitted to the filter capacitor CS and the driver 10 respectively through the first diode D1 and the second diode D2. When the filter capacitor CS is filled with charge, a start current is provided to the motor 1. The driver 10 provides a driving signal to the motor 1 according to the external power VIN to drive the motor 1. The driving signal can be a pulse width modulation (PWM) signal.
When the control system 2 controls the motor 1 to start driving, some problems usually occur. When the switch element S is switched to a turned-on state from a turned-off state, the motor 1 and the filter capacitor CS can be damaged by an in-rush current generated due to the state switch. Moreover, the cost of the switch element S is high since it has to take a larger flowing-through current.